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Java > Open Source Codes > com > sun > org > apache > bcel > internal > generic > LineNumberGen


1 package com.sun.org.apache.bcel.internal.generic;
2
3 /* ====================================================================
4  * The Apache Software License, Version 1.1
5  *
6  * Copyright (c) 2001 The Apache Software Foundation. All rights
7  * reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  * notice, this list of conditions and the following disclaimer.
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  * notice, this list of conditions and the following disclaimer in
18  * the documentation and/or other materials provided with the
19  * distribution.
20  *
21  * 3. The end-user documentation included with the redistribution,
22  * if any, must include the following acknowledgment:
23  * "This product includes software developed by the
24  * Apache Software Foundation (http://www.apache.org/)."
25  * Alternately, this acknowledgment may appear in the software itself,
26  * if and wherever such third-party acknowledgments normally appear.
27  *
28  * 4. The names "Apache" and "Apache Software Foundation" and
29  * "Apache BCEL" must not be used to endorse or promote products
30  * derived from this software without prior written permission. For
31  * written permission, please contact apache@apache.org.
32  *
33  * 5. Products derived from this software may not be called "Apache",
34  * "Apache BCEL", nor may "Apache" appear in their name, without
35  * prior written permission of the Apache Software Foundation.
36  *
37  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
38  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
39  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
40  * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
41  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
44  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
45  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
46  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
47  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
48  * SUCH DAMAGE.
49  * ====================================================================
50  *
51  * This software consists of voluntary contributions made by many
52  * individuals on behalf of the Apache Software Foundation. For more
53  * information on the Apache Software Foundation, please see
54  * <http://www.apache.org/>.
55  */
56
57 import com.sun.org.apache.bcel.internal.Constants;
58 import com.sun.org.apache.bcel.internal.classfile.*;
59
60 /**
61  * This class represents a line number within a method, i.e., give an instruction
62  * a line number corresponding to the source code line.
63  *
64  * @version $Id: LineNumberGen.java,v 1.1.1.1 2001/10/29 20:00:23 jvanzyl Exp $
65  * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
66  * @see LineNumber
67  * @see MethodGen
68  */
69 public class LineNumberGen implements InstructionTargeter, Cloneable JavaDoc {
70   private InstructionHandle ih;
71   private int src_line;
72
73   /**
74    * Create a line number.
75    *
76    * @param ih instruction handle to reference
77    * @return new line number object
78    */
79   public LineNumberGen(InstructionHandle ih, int src_line) {
80     setInstruction(ih);
81     setSourceLine(src_line);
82   }
83
84   /**
85    * @return true, if ih is target of this line number
86    */
87   public boolean containsTarget(InstructionHandle ih) {
88     return this.ih == ih;
89   }
90
91   /**
92    * @param old_ih old target
93    * @param new_ih new target
94    */
95   public void updateTarget(InstructionHandle old_ih, InstructionHandle new_ih) {
96     if(old_ih != ih)
97       throw new ClassGenException("Not targeting " + old_ih + ", but " + ih + "}");
98     else
99       setInstruction(new_ih);
100   }
101
102   /**
103    * Get LineNumber attribute .
104    *
105    * This relies on that the instruction list has already been dumped to byte code or
106    * or that the `setPositions' methods has been called for the instruction list.
107    */
108   public LineNumber getLineNumber() {
109     return new LineNumber(ih.getPosition(), src_line);
110   }
111
112   public void setInstruction(InstructionHandle ih) {
113     BranchInstruction.notifyTarget(this.ih, ih, this);
114
115     this.ih = ih;
116   }
117
118   public Object JavaDoc clone() {
119     try {
120       return super.clone();
121     } catch(CloneNotSupportedException JavaDoc e) {
122       System.err.println(e);
123       return null;
124     }
125   }
126
127   public InstructionHandle getInstruction() { return ih; }
128   public void setSourceLine(int src_line) { this.src_line = src_line; }
129   public int getSourceLine() { return src_line; }
130 }
131
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